The present invention relates to the installation of fuel pumps, fuel level senders and rollover/venting valves for motor vehicle fuel tanks.
In order to provide protection against fuel spilling from the vapor vent line in a fuel tank, in the event of a vehicle rollover, it has been mandated that motor vehicle fuel tanks be equipped with valves which close the vapor vent when the vehicle is tilted beyond a threshold amount from the normal upright position. Such rollover/vent valves typically employ a float which closes the valve when the liquid level of the fuel rises above a predetermined level in order to prevent liquid fuel from sloshing out of the vapor vent either during normal operation or in the event of rollover. Further, it is necessary to locate the valve in the highest portion or the location of the deepest fuel level in order to provide vapor venting at all levels of fuel up to the maximum fuel level.
Heretofore, such rollover/vent valves have been installed through an access opening provided in the fuel tank at the highest location thereon and sealed and secured over the opening.
This requirement for the placement of the rollover/vent valve has required plural access openings in the top of the fuel tank in order to properly locate the rollover/vent valve and also to provide an access opening for the installation of the fuel pump and level sender mechanism for providing remote readout of the fuel level to the vehicle operator. The plural access openings in the top of the fuel tank require a seal around each opening and thus the probability of a faulty seal and leakage has been increased. In addition the need for plural access openings has weakened the structural integrity of the top of the fuel tank and has increased the cost of fabricating the tank.
Furthermore, in many of the recent passenger and light truck vehicle designs, it has been necessary to provide a dished out or recessed area in the top of the fuel tank in order to properly locate and fit the fuel tank underneath the vehicle platform. This structural arrangement has made it extremely difficult to provide installation and connection of the vapor vent lines to the rollover/vent valve upon installation of the tank onto the vehicle during vehicle assembly. Such an arrangement has also complicated the routing of the vent and fuel feed lines and the electric supply leads to the fuel pump.
It has thus long been desired to find a way or means of simplifying the installation of the rollover/vent valve, fuel pump and fuel sender devices onto a fuel tank in a manner which reduces the number of access openings in the top of the tank and enables all the lines to be commonly routed to a single access opening. It has further been desirable to eliminate the plural access openings in the top of the fuel tank to reduce the number of areas requiring seals and thus the probability of leakage in the event of faulty sealing either during installation or in service.